Fred played in Pato's absence in this month's friendlies against the Netherlands, a 0-0 draw in Gioania, and a 1-0 win over Romania in Sao Paulo in which he scored the only goal.
"I'm 100 percent, because if I was injured I wouldn't be here," AC Milan's Pato told reporters as the Brazil squad assembled in Rio for Tuesday's departure to Argentina for the July 1-24 tournament.
"I'm OK and I respect Fred, but I'm going to work to play in the number nine shirt. I'll play my football and help the national team seek that title."
Pato said the Copa America, coach Mano Menezes' first competition in charge of Brazil, has an additional importance because as 2014 World Cup hosts they will not be playing the South American qualifiers and will miss competitive action.
"Despite not playing the qualifiers, we'll make the Copa America a test for Brazil and I'm confident," he said.
Brazil, who beat Argentina in the last two finals of Copa America in 2004 and 2007, meet Venezuela in their opening match in La Plata on July 3.
They face Paraguay and Ecuador in Cordoba on July 9 and 13 in their other Group B matches.
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